Field of the Invention
The invention relates to an exhaust-gas turbocharger.
Description of the Related Art
An exhaust-gas turbocharger of this type is known from U.S. Pat. No. 7,287,960 B2. The rotor of this known exhaust-gas turbocharger is formed by a turbine wheel having a connecting journal on the wheel rear side thereof. The connecting journal is inserted into a cavity in a shaft shoulder of the shaft of the exhaust-gas turbocharger. In this respect, it is possible to leave a clearance, which can serve as a heat throttle, between the end face of the journal and the opposite side of the cavity in the shaft shoulder. In a manner related to construction and primarily on account of the required strength of the connection between the journal and the shaft shoulder, however, this heat throttle can be formed so as to be only relatively short owing to its position between the end face and the adjacent wall of the shaft shoulder.
It is an object of the present invention, therefore, to provide an exhaust-gas turbocharger, the heat throttle of which can be dimensioned in such a manner that an excessive introduction of heat from the turbine wheel into the shaft can reliably be avoided.